The development of tomato varieties is desired for commercial
production in agricultural areas having relatively
low spring temperatures, and/or short growing seasons. These
varieties would need the character of being able to set fruit
under the unfavorable conditions of temperatures below 65 F.
the English variety. Puck, has the characteristic of setting
fruit at low temperatures, but is otherwise unsuitable for
profitable tomato production. To identify the mechanism of
this desirable character in Puck, and mode of inheritance of
the character, experiments were carried out to study flower
production, pollen compatibility relationships, and the production,
development and germination of pollen.
Experiments were carried out at two temperature levels
in greenhouses to observe effects on flower and fruit development.
These plant responses were studied in a relatively cool
greenhouse kept at 55°- 65° F. and in another house kept at 65 -
75°P. range which is considered optimum for tomato production.
The plants used were Puck and Bonny Best varieties and their
reciprocal F1 hybrids.
Blower production was significantly increased by lower
temperatures, and the increases on Puck and the hybrids were
larger than on Bonny Best. Fruit setting was reduced by low
temperatures, suggesting reduction of self-compatibility in
the hybrids as well as in Bonny Best, the latter having a high percentage of parthenocarpic fruits. The number of days
between pollination and maturity of fruits was found to be in versely
related to the number of seed formed in the fruits.
Low temperatures, probably interacting with low light
intensities and short photoperiods, appeared to reduce markedly
the viability of pollen on all lines, as shown by viability
tests on the pollen with the acetocarmine staining procedure
and with germination tests in vitro. These experiments revealed
an unexpected variability in pollen germination, which was
possibly due to the effects of temperature on microsporogenesis.
Percentages of normal meioses were only slightly affected, but
there was evidence that a minimum temperature is required for
the completion of meiosis, and that such minima were different
for different meiotic stages. Rates of pollen deterioration
following dehiscence of the anthers were found to be different
in different varieties.
Puck had a higher number of flowers produced at low temperatures
showed no reduction of self-compatibility, and had a
consistent seed set; therefore, this variety is to be considered
a possible source of germ plasm in the breeding of tomatoes
tolerant of cool temperatures. / Land and Food Systems, Faculty of / Graduate
Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/41670 |
Date | January 1959 |
Creators | Guccione, Gioacchino Maria |
Publisher | University of British Columbia |
Source Sets | University of British Columbia |
Language | English |
Detected Language | English |
Type | Text, Thesis/Dissertation |
Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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